1. Field of the Invention
The present invention relates to an IC (integrated circuit) card with a built-in IC chip, particularly, a card with a built-in electronic part, which is suitable for use as a credit card, bank card, prepaid card, patient's registration card, membership card or the like, and a production process thereof.
2. Related Background Art
Various kinds of information have heretofore been stored in cards such as credit cards, bank cards, prepaid cards, patient's registration cards and membership cards. As a method for recording information, there is used the so-called optical card system in which information is digitized, and magnetism, bar code or laser beam is used to volatilize out a part of an optical recording layer on an information recording medium, or to cause a change in reflectance of the optical recording layer, or to cause deformation thereof, thereby recording and reproducing the information by an optical difference in reflectance or transmittance. Besides, embossing in which recesses and projections are formed in and on a card, and characters and numerals are expressed by the projections, or general printing such as screen printing or offset printing may also be used as a method for recording information.
In recent years, IC cards called chip cards, memory cards, microcomputer cards or electronic cards, in which an IC chip has been mounted, have begun to be used.
Such IC cards have a great storage capacity compared with the conventional cards using magnetism or bar code, and so it is attempted to store account data in place of bankbooks in bank connections, and data of transactions such as shopping in credit connections in these IC cards. They are also used as oil cards for gas stations and are put to practical use in not only the transaction data but also various services.
However, the data are not directly visible to the naked eyes in magnetic recording and bar codes, in which the information is digitized and stored, or optical cards. It is therefore difficult to check the information stored in the card as to whether the information is truly that as to its owner or not.
Printing of matters to be attended to use, codes, etc. by character information, and printing of logo, underground pattern, design, etc. are generally performed by general printing such as screen printing or offset printing. However, such printing requires to make plates corresponding to the number of colors used in the printing, and so it is difficult to make them in a short period of time. In addition, the unit cost of production becomes very high in small-quantity production. Such printing is limited to uniform information, and individual information is separately recorded by the above-described digital data under circumstances.
It is partially practiced to record individual information, for example, a portrait of the owner of a card on the card.
However, it is difficult to make the card in a short period of time by a method comprising sticking a photograph itself on the card. Such a method is also high in cost.
A method using sublimate type thermal transfer printing involves a drawback that the cost of an ink ribbon is high, and running cost thus becomes high. When full-color printing is performed in particular, it is not economical because ink ribbons of 3 colors of yellow, magenta and cyan are always consumed irrespective of optical density. Since the ink ribbon is in the form of a thin film, it may have been damaged in some cases by lack of experience when it has been installed in a printer. There has been also a limitation that a material of a base on which printing is performed must be selected from those fit for the sublimate type thermal transfer printing. In addition, a printing head is of a contact type that it comes into contact with a printing surface through an ink ribbon. Therefore, a fine print may not be provided due to delicate irregularities on the printing surface, or the ink ribbon is not brought into fully close contact with the printing surface when foreign matter such as dust is present on the surface of a card, so that printing failure may occur in some cases. Further, it is generally not practiced to conduct printing up to the end of a card, since the printing head has a possibility of coming into contact with the edge face of the card and hence of its being damaged. Therefore, a blank is provided at the edge face of the card.
As a method for solving these problems, there is investigated a method comprising providing an ink-receiving layer on the surface of a card and conducting printing thereon by an ink-jet system as described in Japanese Patent Application Laid-Open Nos. 58-96592 (1983) and 1-43826 (1989). According to this method, the above-described problems can be avoided because a printing head is of a non-contact type.
As a method for fabricating an IC card, there is a method in which a recess for mounting an IC module is provided in the surface of a card by machining, and the IC module, on which necessary mounting has been made, is then joined. This method is described in Japanese Registered Utility Model Publication No. 2557356. When a card on which an ink-receiving layer has been provided is used to fabricate an IC card by such a method, however, there are involved problems that the ink-receiving layer cannot be finely machined to cause burr, and a resin component in the ink-receiving layer adheres to a working tool when the machining is continuously conducted, and so reduction of machining speed and lowering of machining accuracy are incurred. Therefore, deburring is required as post working, and tooling must be frequently conducted. Therefore, this process cannot choose but become a process low in productivity. Therefore, it has been unavoidable for the cost of the card to increase. The above publication dose not describe anything about the provision of the ink-receiving layer, so that no method for solving this problem is described.